There's a link to an entertaining video on "The Mirrorless Revolution" over at this Luminous Landscape page as well as a brief description of some of the major players.

I've always had a lot of time for Michael Reichmann and his comments about Canon, a system I dropped in favour of CSC/mirrorless a while back, and Nikon strike a real chord with me. Those "brontosaur" cameras will still be tools of choice for an ever diminishing few but for the rest of us...